-ir and -er ending verbs are very similar in their endings when they are conjugated. how do they differ in their endings when they are conjugated?

When conjugating verbs in Spanish, the -er and -ir ending verbs do share some similarities, but they also have differences in their conjugation endings. Here's how they differ:

1. Present tense:
For -er verbs, the endings in the present tense are:
- yo: -o
- tú: -es
- él/ella/usted: -e
- nosotros/nosotras: -emos
- vosotros/vosotras: -éis
- ellos/ellas/ustedes: -en

For example, the verb "comer" (to eat) in the present tense is conjugated as:
- yo como
- tú comes
- él/ella/usted come
- nosotros/nosotras comemos
- vosotros/vosotras coméis
- ellos/ellas/ustedes comen

For -ir verbs, the endings in the present tense are:
- yo: -o
- tú: -es
- él/ella/usted: -e
- nosotros/nosotras: -imos
- vosotros/vosotras: -ís
- ellos/ellas/ustedes: -en

For example, the verb "vivir" (to live) in the present tense is conjugated as:
- yo vivo
- tú vives
- él/ella/usted vive
- nosotros/nosotras vivimos
- vosotros/vosotras vivís
- ellos/ellas/ustedes viven

Notice that the only difference between the -er and -ir endings in the present tense is in the nosotros/nosotras and vosotros/vosotras forms.

2. Preterite tense:
-er verbs and -ir verbs also differ in their preterite tense endings. Here's a comparison:

For -er verbs, the preterite tense endings are:
- yo: -í
- tú: -iste
- él/ella/usted: -ió
- nosotros/nosotras: -imos
- vosotros/vosotras: -isteis
- ellos/ellas/ustedes: -ieron

For example, the -er verb "beber" (to drink) in the preterite tense is:
- yo bebí
- tú bebiste
- él/ella/usted bebió
- nosotros/nosotras bebimos
- vosotros/vosotras bebisteis
- ellos/ellas/ustedes bebieron

For -ir verbs, the preterite tense endings are:
- yo: -í
- tú: -iste
- él/ella/usted: -ió
- nosotros/nosotras: -imos
- vosotros/vosotras: -isteis
- ellos/ellas/ustedes: -ieron

For example, the -ir verb "escribir" (to write) in the preterite tense is:
- yo escribí
- tú escribiste
- él/ella/usted escribió
- nosotros/nosotras escribimos
- vosotros/vosotras escribisteis
- ellos/ellas/ustedes escribieron

As you can see, the endings for both -er and -ir verbs are identical in the preterite tense. The only difference lies in the stems of the verbs.

By understanding the specific endings for each tense, you can conjugate -er and -ir verbs correctly in Spanish.

The only thing I know to suggest is to google these topics and read all you can find.

Conjugate Spanish -er verbs

Conjugate Spanish -ir verbs